Epidemiological characteristics of the 2019 Measles outbreak in central Tunisia

Abstract Background Measles is still an important public health problem worldwide causing significant morbidity and mortality. Measles represents a vaccine-preventable disease. In Tunisia, vaccination against measles was launched in 1983. In spite of the progress made towards measles elimination, Tunisia experienced an outbreak in 2019. We aimed to describe the measles outbreak in the central region of Tunisia in 2019. Methods We carried out a descriptive study using surveillance data from January to December 2019 in four governorates in Tunisia (Monastir, Mahdia, Kairouan, and Kasserine). All suspected measles cases and declared to regional directorate of primary health care were included. A suspected measles case was defined as any person with fever and generalized maculo-papular rash plus one of the following symptoms: cough or coryza or conjunctivitis. A laboratory confirmed measles case is a suspected case of measles that has been confirmed positive by testing (IgM+). Results A total of 2,688 suspected cases were recorded, of which 369 cases were (14.7%) were confirmed measles through serological testing. The sex ratio was 1.06 for suspected cases and 1.12 for measles cases. Infants under one year old accounted 42.2% of suspected cases. The majority of suspected cases (67.3%) were not vaccinated. Among confirmed measles cases, positivity rates were 81.8% for unvaccinated, 70.0% for those with one dose and 27.2% for those with two doses. The hospitalization rate was 61.5 %; highest rates were observed in infants under one year of age (65.7%) and in the age group over 38 years (69.0%). In total, 27 deaths were reported. The highest lethality rate was observed in the age group under 12 months (2%). Conclusions The 2019 measles outbreak in Tunisia highlighted that this disease remains a serious viral infection. Unvaccinated populations could be a potential source for new outbreaks, imposing substantial public health burdens. Key messages • The country needs to establish a national review committee to monitor measles elimination status. • To address future challenges, immunity gaps in the population should be closed.